Describe/ explain how environmental factors affect the rate of transpiration.

-Increase in atmospheric/ environmental temperature; increases internal temperature of the leaf; which in turn increases the latent heat of vaporization; leading to high rate of transpiration; decrease in atmospheric/ environmental temperature lowers internal temperature of the leaf; decreasing the rate of evaporation of water from the mesophyll cells of the leaf; thus lowering the rate of transpiration;
-Strong wind; blows away moist air from around the leaf; thus increasing diffusion gradient/ concentration gradient between the sub-stomatal air spaces and atmosphere; thus increasing the rate of transpiration; still air allows accumulation of water vapour around the leaf; lowering the concentration gradient consequently lowering the rate of transpiration;
-Higher humidity; reduces the diffusion gradient/ concentration gradient between the sub-stomatal air spaces and atmosphere; thus decreasing the rate of transpiration; Lower humidity; increases the diffusion gradient/ concentration gradient between the sub-stomatal air spaces and atmosphere; thus increasing the rate of transpiration.
-Increase in light intensity; stimulates stomatal opening due to uptake of water by guard cells; leading to rapid rate of evaporation thus increasing the rate of transpiration. Low light intensity reduces the opening of stomata hence low rate of transpiration;
-Increase in atmospheric pressure holds more water vapour in the atmosphere; reducing the concentration gradient/concentration deficit; hence reduces the rate of transpiration. Lower atmospheric pressure can hold less water vapour in the atmosphere; increasing the concentration gradient/concentration deficit; hence increasing the rate of transpiration.
-Adequate supply of water makes the walls of mesophyll cells get saturated with water increasing transpiration rate; inadequate water supply reduces saturation in the walls of mesophyll cells; hence less water evaporates into intercellular spaces thus reducing the rate of transpiration;